gecko-dev/dom/base/AttrArray.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/*
* Storage of the children and attributes of a DOM node; storage for
* the two is unified to minimize footprint.
*/
#include "AttrArray.h"
#include "mozilla/CheckedInt.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/MemoryReporting.h"
#include "nsMappedAttributeElement.h"
#include "nsString.h"
#include "nsHTMLStyleSheet.h"
#include "nsMappedAttributes.h"
#include "nsUnicharUtils.h"
#include "nsContentUtils.h" // nsAutoScriptBlocker
using mozilla::CheckedUint32;
AttrArray::Impl::~Impl()
{
for (InternalAttr& attr : NonMappedAttrs()) {
attr.~InternalAttr();
}
NS_IF_RELEASE(mMappedAttrs);
}
const nsAttrValue*
AttrArray::GetAttr(nsAtom* aLocalName, int32_t aNamespaceID) const
{
if (aNamespaceID == kNameSpaceID_None) {
// This should be the common case so lets make an optimized loop
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName)) {
return &attr.mValue;
}
}
if (mImpl && mImpl->mMappedAttrs) {
return mImpl->mMappedAttrs->GetAttr(aLocalName);
}
} else {
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName, aNamespaceID)) {
return &attr.mValue;
}
}
}
return nullptr;
}
const nsAttrValue*
AttrArray::GetAttr(const nsAString& aLocalName) const
{
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName)) {
return &attr.mValue;
}
}
if (mImpl && mImpl->mMappedAttrs) {
return mImpl->mMappedAttrs->GetAttr(aLocalName);
}
return nullptr;
}
const nsAttrValue*
AttrArray::GetAttr(const nsAString& aName,
nsCaseTreatment aCaseSensitive) const
{
// Check whether someone is being silly and passing non-lowercase
// attr names.
if (aCaseSensitive == eIgnoreCase &&
nsContentUtils::StringContainsASCIIUpper(aName)) {
// Try again with a lowercased name, but make sure we can't reenter this
// block by passing eCaseSensitive for aCaseSensitive.
nsAutoString lowercase;
nsContentUtils::ASCIIToLower(aName, lowercase);
return GetAttr(lowercase, eCaseMatters);
}
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.QualifiedNameEquals(aName)) {
return &attr.mValue;
}
}
if (mImpl && mImpl->mMappedAttrs) {
return mImpl->mMappedAttrs->GetAttr(aName);
}
return nullptr;
}
const nsAttrValue*
AttrArray::AttrAt(uint32_t aPos) const
{
NS_ASSERTION(aPos < AttrCount(),
"out-of-bounds access in AttrArray");
uint32_t nonmapped = NonMappedAttrCount();
if (aPos < nonmapped) {
return &mImpl->NonMappedAttrs()[aPos].mValue;
}
return mImpl->mMappedAttrs->AttrAt(aPos - nonmapped);
}
template<typename Name>
inline nsresult
AttrArray::AddNewAttribute(Name* aName, nsAttrValue& aValue)
{
MOZ_ASSERT(!mImpl || mImpl->mCapacity >= mImpl->mAttrCount);
if (!mImpl || mImpl->mCapacity == mImpl->mAttrCount) {
if (!GrowBy(1)) {
return NS_ERROR_OUT_OF_MEMORY;
}
}
InternalAttr& attr = mImpl->mBuffer[mImpl->mAttrCount++];
new (&attr.mName) nsAttrName(aName);
new (&attr.mValue) nsAttrValue();
attr.mValue.SwapValueWith(aValue);
return NS_OK;
}
nsresult
AttrArray::SetAndSwapAttr(nsAtom* aLocalName, nsAttrValue& aValue,
bool* aHadValue)
{
*aHadValue = false;
for (InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName)) {
attr.mValue.SwapValueWith(aValue);
*aHadValue = true;
return NS_OK;
}
}
return AddNewAttribute(aLocalName, aValue);
}
nsresult
AttrArray::SetAndSwapAttr(mozilla::dom::NodeInfo* aName,
nsAttrValue& aValue, bool* aHadValue)
{
int32_t namespaceID = aName->NamespaceID();
nsAtom* localName = aName->NameAtom();
if (namespaceID == kNameSpaceID_None) {
return SetAndSwapAttr(localName, aValue, aHadValue);
}
*aHadValue = false;
for (InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(localName, namespaceID)) {
attr.mName.SetTo(aName);
attr.mValue.SwapValueWith(aValue);
*aHadValue = true;
return NS_OK;
}
}
return AddNewAttribute(aName, aValue);
}
nsresult
AttrArray::RemoveAttrAt(uint32_t aPos, nsAttrValue& aValue)
{
NS_ASSERTION(aPos < AttrCount(), "out-of-bounds");
uint32_t nonmapped = NonMappedAttrCount();
if (aPos < nonmapped) {
mImpl->mBuffer[aPos].mValue.SwapValueWith(aValue);
mImpl->mBuffer[aPos].~InternalAttr();
memmove(mImpl->mBuffer + aPos,
mImpl->mBuffer + aPos + 1,
(mImpl->mAttrCount - aPos - 1) * sizeof(InternalAttr));
--mImpl->mAttrCount;
return NS_OK;
}
if (MappedAttrCount() == 1) {
// We're removing the last mapped attribute. Can't swap in this
// case; have to copy.
aValue.SetTo(*mImpl->mMappedAttrs->AttrAt(0));
NS_RELEASE(mImpl->mMappedAttrs);
return NS_OK;
}
RefPtr<nsMappedAttributes> mapped =
GetModifiableMapped(nullptr, nullptr, false);
mapped->RemoveAttrAt(aPos - nonmapped, aValue);
return MakeMappedUnique(mapped);
}
mozilla::dom::BorrowedAttrInfo
AttrArray::AttrInfoAt(uint32_t aPos) const
{
NS_ASSERTION(aPos < AttrCount(),
"out-of-bounds access in AttrArray");
uint32_t nonmapped = NonMappedAttrCount();
if (aPos < nonmapped) {
InternalAttr& attr = mImpl->mBuffer[aPos];
return BorrowedAttrInfo(&attr.mName, &attr.mValue);
}
return BorrowedAttrInfo(
mImpl->mMappedAttrs->NameAt(aPos - nonmapped),
mImpl->mMappedAttrs->AttrAt(aPos - nonmapped));
}
const nsAttrName*
AttrArray::AttrNameAt(uint32_t aPos) const
{
NS_ASSERTION(aPos < AttrCount(),
"out-of-bounds access in AttrArray");
uint32_t nonmapped = NonMappedAttrCount();
if (aPos < nonmapped) {
return &mImpl->mBuffer[aPos].mName;
}
return mImpl->mMappedAttrs->NameAt(aPos - nonmapped);
}
const nsAttrName*
AttrArray::GetSafeAttrNameAt(uint32_t aPos) const
{
uint32_t nonmapped = NonMappedAttrCount();
if (aPos < nonmapped) {
return &mImpl->mBuffer[aPos].mName;
}
if (aPos >= AttrCount()) {
return nullptr;
}
return mImpl->mMappedAttrs->NameAt(aPos - nonmapped);
}
const nsAttrName*
AttrArray::GetExistingAttrNameFromQName(const nsAString& aName) const
{
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.QualifiedNameEquals(aName)) {
return &attr.mName;
}
}
if (mImpl && mImpl->mMappedAttrs) {
return mImpl->mMappedAttrs->GetExistingAttrNameFromQName(aName);
}
return nullptr;
}
int32_t
AttrArray::IndexOfAttr(nsAtom* aLocalName, int32_t aNamespaceID) const
{
if (!mImpl) {
return -1;
}
int32_t idx;
if (mImpl->mMappedAttrs && aNamespaceID == kNameSpaceID_None) {
idx = mImpl->mMappedAttrs->IndexOfAttr(aLocalName);
if (idx >= 0) {
return NonMappedAttrCount() + idx;
}
}
uint32_t i = 0;
if (aNamespaceID == kNameSpaceID_None) {
// This should be the common case so lets make an optimized loop
// Note that here we don't check for AttrSlotIsTaken() in the loop
// condition for the sake of performance because comparing aLocalName
// against null would fail in the loop body (since Equals() just compares
// the raw pointer value of aLocalName to what AttrSlotIsTaken() would be
// checking.
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName)) {
return i;
}
++i;
}
} else {
for (const InternalAttr& attr : NonMappedAttrs()) {
if (attr.mName.Equals(aLocalName, aNamespaceID)) {
return i;
}
++i;
}
}
return -1;
}
nsresult
AttrArray::SetAndSwapMappedAttr(nsAtom* aLocalName,
nsAttrValue& aValue,
nsMappedAttributeElement* aContent,
nsHTMLStyleSheet* aSheet,
bool* aHadValue)
{
bool willAdd = true;
if (mImpl && mImpl->mMappedAttrs) {
willAdd = !mImpl->mMappedAttrs->GetAttr(aLocalName);
}
RefPtr<nsMappedAttributes> mapped =
GetModifiableMapped(aContent, aSheet, willAdd);
mapped->SetAndSwapAttr(aLocalName, aValue, aHadValue);
return MakeMappedUnique(mapped);
}
nsresult
AttrArray::DoSetMappedAttrStyleSheet(nsHTMLStyleSheet* aSheet)
{
MOZ_ASSERT(mImpl && mImpl->mMappedAttrs,
"Should have mapped attrs here!");
if (aSheet == mImpl->mMappedAttrs->GetStyleSheet()) {
return NS_OK;
}
RefPtr<nsMappedAttributes> mapped =
GetModifiableMapped(nullptr, nullptr, false);
mapped->SetStyleSheet(aSheet);
return MakeMappedUnique(mapped);
}
nsresult
AttrArray::DoUpdateMappedAttrRuleMapper(nsMappedAttributeElement& aElement)
{
MOZ_ASSERT(mImpl && mImpl->mMappedAttrs, "Should have mapped attrs here!");
// First two args don't matter if the assert holds.
RefPtr<nsMappedAttributes> mapped =
GetModifiableMapped(nullptr, nullptr, false);
mapped->SetRuleMapper(aElement.GetAttributeMappingFunction());
return MakeMappedUnique(mapped);
}
void
AttrArray::Compact()
{
if (!mImpl) {
return;
}
if (!mImpl->mAttrCount && !mImpl->mMappedAttrs) {
mImpl.reset();
return;
}
// Nothing to do.
if (mImpl->mAttrCount == mImpl->mCapacity) {
return;
}
Impl* impl = mImpl.release();
impl = static_cast<Impl*>(
realloc(impl, Impl::AllocationSizeForAttributes(impl->mAttrCount)));
MOZ_ASSERT(impl, "failed to reallocate to a smaller buffer!");
impl->mCapacity = impl->mAttrCount;
mImpl.reset(impl);
}
uint32_t
AttrArray::DoGetMappedAttrCount() const
{
MOZ_ASSERT(mImpl && mImpl->mMappedAttrs);
return static_cast<uint32_t>(mImpl->mMappedAttrs->Count());
}
nsresult
AttrArray::ForceMapped(nsMappedAttributeElement* aContent, nsIDocument* aDocument)
{
nsHTMLStyleSheet* sheet = aDocument->GetAttributeStyleSheet();
RefPtr<nsMappedAttributes> mapped = GetModifiableMapped(aContent, sheet, false, 0);
return MakeMappedUnique(mapped);
}
void
AttrArray::ClearMappedServoStyle()
{
if (mImpl && mImpl->mMappedAttrs) {
mImpl->mMappedAttrs->ClearServoStyle();
}
}
nsMappedAttributes*
AttrArray::GetModifiableMapped(nsMappedAttributeElement* aContent,
nsHTMLStyleSheet* aSheet,
bool aWillAddAttr,
int32_t aAttrCount)
{
if (mImpl && mImpl->mMappedAttrs) {
return mImpl->mMappedAttrs->Clone(aWillAddAttr);
}
MOZ_ASSERT(aContent, "Trying to create modifiable without content");
nsMapRuleToAttributesFunc mapRuleFunc =
aContent->GetAttributeMappingFunction();
return new (aAttrCount) nsMappedAttributes(aSheet, mapRuleFunc);
}
nsresult
AttrArray::MakeMappedUnique(nsMappedAttributes* aAttributes)
{
NS_ASSERTION(aAttributes, "missing attributes");
if (!mImpl && !GrowBy(1)) {
return NS_ERROR_OUT_OF_MEMORY;
}
if (!aAttributes->GetStyleSheet()) {
// This doesn't currently happen, but it could if we do loading right
RefPtr<nsMappedAttributes> mapped(aAttributes);
mapped.swap(mImpl->mMappedAttrs);
return NS_OK;
}
RefPtr<nsMappedAttributes> mapped =
aAttributes->GetStyleSheet()->UniqueMappedAttributes(aAttributes);
NS_ENSURE_TRUE(mapped, NS_ERROR_OUT_OF_MEMORY);
if (mapped != aAttributes) {
// Reset the stylesheet of aAttributes so that it doesn't spend time
// trying to remove itself from the hash. There is no risk that aAttributes
// is in the hash since it will always have come from GetModifiableMapped,
// which never returns maps that are in the hash (such hashes are by
// nature not modifiable).
aAttributes->DropStyleSheetReference();
}
mapped.swap(mImpl->mMappedAttrs);
return NS_OK;
}
const nsMappedAttributes*
AttrArray::GetMapped() const
{
return mImpl ? mImpl->mMappedAttrs : nullptr;
}
nsresult
AttrArray::EnsureCapacityToClone(const AttrArray& aOther)
{
MOZ_ASSERT(!mImpl, "AttrArray::EnsureCapacityToClone requires the array be empty when called");
uint32_t attrCount = aOther.NonMappedAttrCount();
if (!attrCount) {
return NS_OK;
}
// No need to use a CheckedUint32 because we are cloning. We know that we
// have already allocated an AttrArray of this size.
mImpl.reset(static_cast<Impl*>(malloc(
Impl::AllocationSizeForAttributes(attrCount))));
NS_ENSURE_TRUE(mImpl, NS_ERROR_OUT_OF_MEMORY);
mImpl->mMappedAttrs = nullptr;
mImpl->mCapacity = attrCount;
mImpl->mAttrCount = 0;
return NS_OK;
}
bool
AttrArray::GrowBy(uint32_t aGrowSize)
{
const uint32_t kLinearThreshold = 16;
const uint32_t kLinearGrowSize = 4;
CheckedUint32 capacity = mImpl ? mImpl->mCapacity : 0;
CheckedUint32 minCapacity = capacity;
minCapacity += aGrowSize;
if (!minCapacity.isValid()) {
return false;
}
if (capacity.value() <= kLinearThreshold) {
do {
capacity += kLinearGrowSize;
if (!capacity.isValid()) {
return false;
}
} while (capacity.value() < minCapacity.value());
} else {
uint32_t shift = mozilla::CeilingLog2(minCapacity.value());
if (shift >= 32) {
return false;
}
capacity = 1u << shift;
}
CheckedUint32 sizeInBytes = capacity.value();
sizeInBytes *= sizeof(InternalAttr);
if (!sizeInBytes.isValid()) {
return false;
}
sizeInBytes += sizeof(Impl);
if (!sizeInBytes.isValid()) {
return false;
}
MOZ_ASSERT(sizeInBytes.value() ==
Impl::AllocationSizeForAttributes(capacity.value()));
const bool needToInitialize = !mImpl;
Impl* newImpl = static_cast<Impl*>(realloc(mImpl.release(), sizeInBytes.value()));
NS_ENSURE_TRUE(newImpl, false);
mImpl.reset(newImpl);
// Set initial counts if we didn't have a buffer before
if (needToInitialize) {
mImpl->mMappedAttrs = nullptr;
mImpl->mAttrCount = 0;
}
mImpl->mCapacity = capacity.value();
return true;
}
size_t
AttrArray::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
{
size_t n = 0;
if (mImpl) {
// Don't add the size taken by *mMappedAttrs because it's shared.
n += aMallocSizeOf(mImpl.get());
for (const InternalAttr& attr : NonMappedAttrs()) {
n += attr.mValue.SizeOfExcludingThis(aMallocSizeOf);
}
}
return n;
}